JP2013543672A - Multi-user multi-input multi-output wireless communication device, system and method - Google Patents

Abstract

A multi-user multiple-input multiple-output (MIMO) wireless communication device, system, and method are provided.
In some embodiments, a wireless communication device (102) receives a plurality of channel feedback transmissions from each of a plurality of user devices (104, 106, 108), of the plurality of user devices. One channel feedback transmission from one user device includes partial information regarding a MIMO channel matrix between the wireless communication unit and one user device, and the wireless communication device (102) can perform multi-user MIMO according to the MIMO beamforming scheme. The transmission is transmitted to multiple user devices, and the MIMO beamforming scheme is based on multiple channel feedback transmissions.
[Selection] Figure 1

Description

  In a wireless communication system, a multi-user (MU) multiple-input multiple-output (MIMO) scheme may be implemented.

  The multi-user MIMO scheme is regarded as an effective method for realizing high throughput performance in a wireless communication system.

  A wireless communication device (“station”) uses a plurality of transmission antennas and simultaneously performs a plurality of MIMO transmissions to a plurality of wireless communication devices (“users”) each using a plurality of reception antennas. And / or the station uses a plurality of receiving antennas to simultaneously receive a plurality of MIMOs from a plurality of users.

  By using an adaptive beamforming algorithm such as a Block Diagoniaization (BD) beamforming algorithm or a Regularized Block Diagrationation (RBD) beamforming algorithm at a station, it is possible to support multiple spatial streams per user for multiuser MIMO transmission. Become.

For simplicity and clarity of illustration, elements shown in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to the dimensions of other elements for clarity of presentation. Moreover, the same reference numbers may be repeated among different drawings to indicate corresponding or similar elements. The drawings are as follows.
FIG. 1 is a block diagram that schematically illustrates a system in accordance with some exemplary embodiments. FIG. 2 is a flowchart schematically illustrating a method of wireless communication according to some exemplary embodiments. FIG. 3 is a graph of signal-to-noise ratio (SNR) for multi-user multiple-input multiple-output (MIMO) transmission with channel feedback including partial MIMO channel information, according to some exemplary embodiments. It is a graph showing an ergodic capacity roughly. FIG. 4 is a flowchart that schematically illustrates a method of wireless communication, according to some example embodiments. FIG. 5 schematically represents ergodic capacity as a function of SNR for multi-user MIMO transmission utilizing channel feedback including channel quality indication and partial MIMO channel information, in accordance with some exemplary embodiments. It is a graph. FIG. 6 is a schematic diagram of an article according to some exemplary embodiments.

  In the following description, numerous specific details are set forth in order to provide a thorough understanding of some embodiments. However, one of ordinary skill in the art appreciates that several embodiments can be practiced without these specific details. In other instances, well-known methods, procedures, components, units, and / or circuit descriptions are not provided in order to avoid obscuring the description.

  Descriptions herein using terms such as “processing”, “operation”, “calculation”, “determination”, “establishment”, “analysis”, “confirmation” are described in terms of physical quantities (in a computer register and / or memory). For example, data represented as an electronic quantity) to other data similarly represented as a physical quantity in a computer register and / or memory, or other information storage medium capable of storing instructions for performing operations and / or processes. May refer to the operation and / or processing of a computer, computing platform, computing system, or other electronic computing device that operates and / or transforms.

  As used herein, the term “plurality” includes, for example, the meaning of “many” or “two or more”. For example, “a plurality of items” means “two or more items”.

  Some embodiments can be used in connection with various devices and systems. These various devices and systems include video devices, audio devices, audio / video (A / V) devices, Set-Top-Box (STB), Blu-ray Disc (BD) players, BD recorders, Digital Video Discs (DVD). Player, High Definition (HD) DVD player, DVD recorder, HD DVD recorder, Personal Video Recorder (PVR), Broadcast HD receiver, Video source, Audio source, Video sink, Audio sink, Stereo tuner, Broadcast radio receiver, Display , Flat panel display, personal media player (PMP), digital video camera (DVC), digital Digital audio player, speaker, audio receiver, audio amplifier, data source, data sink, digital still camera (DSC), personal computer (PC), desktop computer, mobile computer, laptop computer, notebook computer, tablet type Computer, Server Computer, Handheld Computer, Handheld Device, Personal Digital Assistant (PDA) Device, Handheld PDA Device, Onboard Device, Offboard Device, Hybrid Device, Vehicle Device, Non-Vehicle Device, Mobile or Portable Device, Consumer Device, non-mobile or non-portable device, wireless communication station, wireless communication Vice, Wireless Access Point (AP), Wired or Wireless Router, Wired or Wireless Modem, Wired or Wireless Network, Wireless Area Network, Wireless Video Area Network (WVAN), Local Area Network (LAN), Wireless LAN (WLAN), Personal Area network (PAN), wireless PAN (WPAN), and the like are included.

  In addition, these various devices and systems may include existing WirelessHD® and / or Wireless-Gigabit-Alliance (WGA) standards and / or their future developed standards and / or standards derived therefrom. Devices and / or networks that operate in compliance, IEEE 802.11 (IEEE 802.11-1999: Wireless LAN Medium Access Control (MAC) and Physical Layers (PHY) Specification), IEEE 802.11n, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g, IEEE 802.11g (TGac) ("IEEE 802.11-09 / 0308r12-TGac Channel Mod el Addendum Document "), IEEE 802.11 task group ad (TGad), IEEE 802.16 (IEEE-Std 802.16, 2009 Edition, Air Interface for 80 E E80, E80 Developed by Edition, Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands, IEEE 802.16m (Task Group Group) And / or existing 3rd Generation Partnership Project (e.g. 3GPP LTE Rel-8) that operates in accordance with standards and / or their future developed standards and / or standards derived therefrom. 3GPP), 3GPP Long term Evolution (LTE), and / or devices and / or networks operating in accordance with any other suitable protocol or standard, units and / or devices that are part of the networks described above, Directional and / or two-way wireless communication systems, cellular wireless telephone communication systems, wireless-display (WiDi) devices, mobile phones, wireless telephones, Personal Co communication systems (PCS) devices, PDA devices with built-in wireless communication devices, mobile or portable Global Positioning System (GPS) devices, devices with GPS receivers or transceivers or chips, devices with RFID elements or chips, MIMO transceivers Or devices, devices with one or more internal and / or external antennas, Digital Video Broadcast (DVB) devices or systems, multi-standard wireless devices or systems, wired or wireless handheld devices (eg BlackBerry, Palm Treo), Wireless Application Protocol (WAP) Deva Scan, and the like.

Some embodiments may be used in connection with one or more wireless communication signals and / or systems. These radio communication signals and / or systems include radio frequency (RF), infrared (IR), frequency division multiplexing (FDM), orthogonal FDM (OFDM), time division multiplexing (TDM), and time division multiple access. (TDMA), extended TDMA (E-TDMA), general packet radio service (GPRS), extended GPRS, code division multiple access (CDMA), wideband CDMA (WCDMA), CDMA 2000, single carrier CDMA, multicarrier CDMA, multi carrier modulation _{(MDM), Discrete Multi-Tone} (DM T), Bluetooth ( registered trademark), Global Positioning System (GPS) , Wi-Fi, Wi-Max, ZigBee ( registered trademark), Ultra-Wideband (UWB , Global System for Mobile Communication (GSM (registered trademark)), 2G, 2.5G, 3G, 3.5G, Enhanced Data Rates for GSM (registered trademark) Evolution (EDGE), 3GPP, includes such 3GPP LTE it is. Other embodiments may be used with various other devices, systems and / or networks.

  The term “wireless device” used in this specification refers to, for example, a device capable of performing wireless communication, a communication device capable of performing wireless communication, a communication station capable of performing wireless communication, and performing wireless communication. Includes portable or non-portable devices that can be used. In some embodiments, a wireless device is or includes a peripheral device that is integrated or attached to a computer. In some embodiments, the term “wireless device” may optionally include wireless services.

  Some embodiments are implemented to provide wireless transmission of appropriate content between two or more devices. In one embodiment, the content includes media content, including audio and / or video content, such as High Definition Television (HDTV) content. In other embodiments, the content includes any other suitable data, information, and / or signals.

  FIG. 1 is a block diagram that schematically illustrates a system 100, according to some exemplary embodiments.

  As shown in FIG. 1, in some embodiments, the system 100 may be a wireless communication device 102, 104, 106 and / or 108, etc., capable of communicating content, data, information and / or signals, for example. A wireless communication network including one or more wireless communication devices. Such content, data, information, and / or signals are communicated over one or more suitable wireless communication channels such as, for example, radio channels, IR channels, RF channels, and Wireless Fidelity (WiFi) channels. One or more elements of the system 100 can optionally communicate over a suitable wired communication link.

  In some exemplary embodiments, the system 100 communicates, manages and / or processes information in accordance with one or more suitable communication standards. For example, the system 100 may include one or more medium access control (MAC) standards, physical layer convergence protocol (PLCP), simple network management protocol (SNMP), asynchronous transmission transfer mode (ATM) protocol, FrameNetRight protocol, FrameNeitRight, ) Protocol, Transport Control Protocol (TCP), Internet Protocol (IP), Hypertext Transfer Protocol (HTTP), User Datagram Protocol (UDP), and the like.

  In some exemplary embodiments, the wireless communication devices 102, 104, 106 and / or 108 are, for example, a PC, a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server. Computers, handheld computers, handheld devices, PDA devices, handheld PDA devices, on-board devices, off-board devices, hybrid devices (eg, a combination of PDA device functions and mobile phone functions), consumer devices, vehicles PDA incorporating device, non-vehicle device, mobile or portable device, non-mobile or non-portable device, mobile phone, PCS device, wireless communication device Vice, mobile or portable GPS devices, DVB devices, relatively small computing devices, non-desktop computers, "Carry Small Live Large" (CSLL) devices, Ultra Mobile Devices (UMD), Ultra Mobile PCs (UMPC), Mobile Internet Device (MID), “Origami” device or computing device, Dynamically Composable Computing (DCC) compatible device, context-aware device, video device, audio device, A / V device, STB, BD player, BD recorder, DVD player , HD DVD player, DVD recorder HD DVD recorder, PVR, broadcast HD receiver, video source, audio source, video sink, audio sink, stereo tuner, broadcast wireless receiver, flat panel display, PMP, DVC, digital audio player, speaker, audio receiver, game Includes devices, audio amplifiers, data sources, data sinks, DSCs, media players, smartphones, televisions, music players, APs, base stations, and the like.

  In some exemplary embodiments, as described below, for example, wireless communication device 110 may be connected to wireless communication devices 104, 106 and / or 108, and / or one or more other wireless communication devices, and multi-user. (MU) The wireless communication part 110 which performs multiple input multiple output (MIMO) wireless communication is included. The wireless communication devices 104, 106 and / or 108 include a wireless communication unit 124 that performs MU MIMO wireless communication with the wireless communication device 102 and / or one or more other wireless communication devices, for example, as described below. It's okay.

  In some exemplary embodiments, the wireless communication devices 102, 104, 106 and / or 108 include, for example, one or more of a processor 118, an input 114, an output 116, a memory unit 120 and a storage device 122. The wireless communication devices 102, 104, 106 and / or 108 optionally include other suitable hardware and / or software components. In some exemplary embodiments, some or all of the components that one or more of the wireless communication devices 102, 104, 106, and / or 108 comprise are covered within a common housing or packaging. In addition, they may be interconnected or operatively associated using one or more wired or wireless links. In other embodiments, the components of one or more of the wireless communication devices 102, 104, 106 and / or 108 are distributed to multiple or independent devices.

  The processor 118 is, for example, a central processing unit (CPU), a digital signal processor (DSP), one or more processor cores, a single core processor, a dual core processor, a multicore processor, a microprocessor, a host processor, a controller, and a plurality of processors. Or a controller, chip, microchip, one or more circuits, circuit elements, logic unit, integrated circuit (IC), application specific IC (ASIC), or any other suitable multi-purpose or application-specific processor or controller including. The processor 114 executes the instructions of the operating system (OS) of the wireless communication device 102, 104, 106 and / or 108, or one or more appropriate applications.

  The input unit 114 includes, for example, a keyboard, a keypad, a mouse, a touchpad, a trackball, a stylus, a microphone, or other appropriate pointing device or input device. The output unit 116 includes, for example, a monitor, screen, flat panel display, cathode ray tube (CRT) display unit, liquid crystal (LCD) display unit, plasma display unit, one or more audio speakers or earphones, or other suitable output device. .

  The memory unit 120 includes, for example, random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), flash memory, volatile memory, nonvolatile memory, cache memory, buffer, Includes short-term memory units, long-term memory units, or other suitable memory units. The storage device 122 includes, for example, a hard disk drive, a floppy disk drive, a compact disk (CD) drive, a CD-ROM drive, a DVD drive, or other suitable removable or non-removable storage device. The memory unit 120 and / or the storage device 122 may store data processed by the wireless communication devices 102, 104, 106 and / or 108, for example.

  In some exemplary embodiments, the wireless communicators 110 and / or 124 transmit and communicate wireless communication signals, RF signals, frames, blocks, transmission streams, packets, messages, data items, and / or data, for example. It includes one or more radio transmitters, receivers, and / or transceivers that can receive. For example, the wireless communication units 110 and / or 124 include or are implemented as a part of a wireless network interface card (NIC).

  In some exemplary embodiments, the wireless communication unit 110 includes or is associated with multiple antennas 120. Each of the wireless communication devices 104, 106 and / or 108 includes or is associated with a plurality of antennas 126, 128 and / or 130. The antennas 120, 126, 128 and / or 130 may include any type of antenna suitable for transmitting and / or receiving wireless communication signals, blocks, frames, transmission streams, packets, messages and / or data. . For example, the antennas 120, 126, 128 and / or 130 may be internal and / or external RF antennas, dipole antennas, monopole antennas, omnidirectional antennas, end-fed antennas, circularly polarized antennas, microstrip antennas, diversity antennas. May include one or more antenna elements, such as, for example, a phased array antenna, a single element antenna, a set of switched beam antennas, a suitable configuration, structure and / or arrangement of components, units and / or arrays. In some embodiments, antennas 120, 126, 128, and / or 130 may implement transmit and receive functions using independent transmit and receive antenna elements. In some embodiments, antennas 120, 126, 128 and / or 130 may implement transmit and receive functions using common and / or integrated transmit / receive elements.

  In some exemplary embodiments, the wireless communicator 110 transmits the MU MIMO transmission 113 to multiple user devices, eg, devices 104, 106 and / or 108, in accordance with a MIMO beamforming (BF) scheme. Send.

  In some exemplary embodiments, MU MIMO transmission 113 includes two or more transmission streams directed to each of devices 104, 106 and / or 108.

  In some exemplary embodiments, the wireless communicator 110 determines the BF scheme used to transmit the MU MIMO transmission 131 to the wireless communication devices 104, 106 and / or 108, eg, as described below. To do.

  MU MIMO transmission to a plurality of users can be performed by a transmitter in conformity with a beam forming method such as a conventional block diagnosis (BD) beam forming method and / or a conventional regularized BD (RBD) beam forming method, for example. Thus, the transmitter is provided with the entire channel matrix between the transmitter and each user. However, the transmission of the entire channel matrix from each user to the transmitter is a cumbersome process, increasing the overhead of MU MIMO communication, reducing throughput, increasing interference, and / or others for MU MIMO communication May have some adverse effects.

  In some exemplary embodiments, a user device of system 100 transmits a channel feedback transmission to wireless communication unit 110 that includes partial information regarding a MIMO channel matrix between wireless communication unit 110 and the user device. For example, the wireless communication unit 124 transmits, to the wireless communication unit 110, channel feedback transmission including partial information regarding a MIMO channel matrix between the wireless communication unit 110 and the wireless communication unit 124, as described below, for example.

  In some exemplary embodiments, the wireless communicator 110 receives multiple channel feedback transmissions from multiple user devices. Here, the channel feedback transmission from one user device of the plurality of user devices includes partial information regarding the MIMO channel matrix between the wireless communication unit and the user device. For example, the wireless communication unit 110 transmits a first channel feedback transmission including partial information regarding a first MIMO channel matrix between the wireless communication unit 110 and the user device 104 from the user device 104, for example, as described below. A second channel feedback transmission including partial information regarding a second MIMO channel matrix between the wireless communication unit 110 and the user device 106 from the device 106 and / or from the user device 108 between the wireless communication unit 110 and the user device 108. A third channel feedback transmission including partial information regarding a third MIMO channel matrix is received.

  In some exemplary embodiments, the channel feedback transmission from one user device represents a plurality of eigenvectors corresponding to the channel matrix between the wireless communication unit 110 and the user device. For example, the first channel feedback transmission is a plurality of eigenvectors corresponding to the MIMO channel matrix between the radio communication unit 110 and the user device 104, and the second channel feedback transmission is between the radio communication unit 110 and the user device 106. The plurality of eigenvectors corresponding to the MIMO channel matrix and / or the third channel feedback transmission represents the plurality of eigenvectors corresponding to the MIMO channel matrix between the wireless communication unit 110 and the user device 108.

  In some exemplary embodiments, the number of eigenvectors represented by the channel feedback transmission from a user device is equal to the number of transmission streams of MU MIMO transmission 113 directed to that user device. For example, the number of eigenvectors represented by the first channel feedback transmission from the user device 104 is equal to the number of transmission streams of the MU MIMO transmission 113 directed to the user device 104 and the second channel feedback transmission from the user device 106 represents. The number of eigenvectors is equal to the number of transmission streams of MU MIMO transmission 113 directed to user device 106 and / or the number of eigenvectors represented by the third channel feedback transmission from user device 108 is directed to user device 108. Equal to the number of transmitted MU MIMO transmission 113 streams.

  In some exemplary embodiments, channel feedback transmission from one user device may include multiple dominations corresponding respectively to multiple dominant eigenvalues of a channel matrix between the wireless communication unit 110 and the user device. Represents a typical eigenvector. For example, the first channel feedback transmission represents a plurality of dominant eigenvectors respectively corresponding to a plurality of dominant eigenvalues of the MIMO channel matrix between the wireless communication unit 110 and the user device 104, and the second channel feedback transmission Represents a plurality of dominant eigenvectors respectively corresponding to a plurality of dominant eigenvalues of the MIMO channel matrix between the wireless communication unit 110 and the user device 106, and / or the third channel feedback transmission A plurality of dominant eigenvectors respectively corresponding to a plurality of dominant eigenvalues of the MIMO channel matrix between the unit 110 and the user device 108.

  In some exemplary embodiments, the channel feedback transmission from the user device includes or represents a quantized value of a plurality of dominant eigenvectors.

  In some exemplary embodiments, feedback transmission from one user device may include a plurality of predefined eigenvectors corresponding to a plurality of eigenvectors of a MIMO channel matrix between the wireless communication unit 110 and the user device. Contains the codebook index that represents. For example, the first channel feedback transmission may be a single codebook index representing a predefined set of codebook eigenvectors corresponding to, for example, a plurality of eigenvectors of a MIMO channel matrix between the wireless communication unit 110 and the user device 104. And the second channel feedback transmission represents a predefined set of codebook eigenvectors corresponding to a plurality of eigenvectors of a MIMO channel matrix between the wireless communication unit 110 and the user device 106, for example. Includes a codebook index, such as a single codebook index, and / or the third channel feedback transmission corresponds to, for example, a plurality of eigenvectors of a MIMO channel matrix between the wireless communication unit 110 and the user device 108 Including a codebook index, such as a single codebook index representing the set of codebook eigenvectors previously defined that.

  In some exemplary embodiments, the codebook index includes a suitable SU MIMO codebook index, such as a preferred matrix index defined in a single user (SU) MIMO transmission scheme. In one example, the codebook index is a codebook index that conforms to an IEEE 802.16 standard, such as the IEEE 802.16m standard, 3GPP LTE, such as 3GPP LTE Rel-8, and / or any other suitable protocol or standard. Including.

  In some exemplary embodiments, the wireless communicator 110 may be configured to transmit the MU MIMO transmission 113 based on a plurality of channel feedback transmissions received from the wireless communication devices 104, 106, and / or 108, eg, as described below. Determine the MIMO beamforming scheme.

  In some exemplary embodiments, the wireless communication unit 110 may use partial information regarding a MIMO channel matrix between the wireless communication unit 110 and a user device, eg, as described below, Modified BD (MBD). A MIMO beamforming scheme for the MU MIMO transmission 113 is determined based on the algorithm and / or the Modified RBD (MRBD) algorithm.

In some exemplary embodiments, the channel feedback transmission from one user device is the eigenvector matrix of the N _ss dominant quantized eigenvector of the MIMO channel matrix between the wireless communication unit 110 and the user device. Represents. Here, N _ss indicates the number of transmission streams of the transmission 113 directed to the user device. In one example, the wireless communication unit 110 transmits an appropriate codebook index representing a matrix of N _ss dominant quantized eigenvectors of a MIMO channel matrix between the wireless communication unit 110 and the wireless communication device 104. 124.

In some exemplary embodiments, the wireless communicators 110 each include N _ss dominant quantized eigenvectors corresponding to each i th user device, eg, based on multiple channel feedback transmissions, A plurality of eigenvector matrices indicated by V _i are determined. Here, i = l. . K, where K refers to the number of users attempting to receive the MU MIMO transmission 113. In one embodiment, the wireless communication unit 110 receives K codebook indexes from each of the K user devices and determines a K matrix V _i based on each of the K codebook indexes. In other embodiments, the wireless communication unit 110 determines the matrix V _i based on any other suitable channel feedback.

In some exemplary embodiments, the wireless communicator 110 transmits a plurality of eigenvectors, such as N _ss dominant quantized eigenvectors corresponding to the i th user device, and each of the plurality of user devices. A MIMO beamforming scheme is determined based on a plurality of corresponding interference matrices. The interference matrix corresponding to the i-th user device may include a plurality of eigenvectors corresponding to other user devices among the plurality of user devices, for example, as described below.

で示す干渉行列は、例えば以下のようにｉ番目のユーザデバイスに関して定義される。

In some exemplary embodiments,

Is defined for the i-th user device as follows, for example.

のＳｉｎｇｌｅ Ｖａｌｕｅ Ｄｅｃｏｍｐｏｓｉｔｉｏｎ（ＳＶＤ）により以下の数式が得られる。

ここで

は、Ｍで示すフィールドの（Ｍ_Ｔ−ｂｙ−Ｍ_Ｔ）ユニタリ行列を指し、フィールドＭには、行列

が含まれる。ここでＭ_Ｔは、無線通信部１１０が送信１１３を実行するのに用いる送信アンテナ１１２の数を指す。ここで

は、対角線に非負実数を有する（Ｍ_Ｔ−ｂｙ−（Ｋ−ｌ）Ｎ_ｓｓ）対角行列を指す。ここで、

は、Ｍの（（Ｋ−ｌ）Ｎ_ｓｓ−ｂｙ−（Ｋ−ｌ）Ｎ_ｓｓ）ユニタリ行列を指す。ここで、

は、

の共役を指す。 In some exemplary embodiments, an interference matrix

The following formula is obtained by Single Value Decomposition (SVD).

here

Denotes a (M _T -by-M _T ) unitary matrix of the field indicated by M.

Is included. Here, M _T indicates the number of transmission antennas 112 used by the wireless communication unit 110 to execute the transmission 113. here

Denotes a diagonal matrix having a non-negative real number on the diagonal (M _T -by- (K−1) N _ss ). here,

Denotes a unitary matrix of M ((K−l) N _ss −by− (K−l) N _ss ). here,

Is

The conjugate of

で示す行列は、ｉ番目のユーザ以外のユーザの全ての支配的な固有ベクトルが生成する空間の基底を決定する。例えば、行列

は、非ゼロの特異値に対応する行列

の固定ベクトルの組を含む。 In some exemplary embodiments,

The matrix shown by determines the base of the space which all the dominant eigenvectors of users other than the i-th user generate. For example, the matrix

Is a matrix corresponding to nonzero singular values

Contains a set of fixed vectors.

で示す第１プリコーディングベクトルは、例えば、ｉ番目のユーザのＭＩＭＯチャネル行列の最大固有値に対応する固有ベクトルなどの行列Ｖ_ｉのＶ_ｉ１で示す第１固有ベクトルを基底

に対して直交させることにより決定される。 In some exemplary embodiments,

Is based on the first eigenvector indicated by V _i1 of the matrix V _i such as the eigenvector corresponding to the maximum eigenvalue of the MIMO channel matrix of the i-th user, for example.

Is determined by making them orthogonal to each other.

で示す更新された基底は、基底

およびプリコーディングベクトル

に基づいて決定される。例えば、更新された基底

は、基底

を第１プリコーディングベクトル

と、例えば以下のように連結することにより決定される。

In some exemplary embodiments,

The updated base indicated by

And precoding vector

To be determined. For example, the updated base

Is the basis

The first precoding vector

For example, it is determined by connecting as follows.

で示す第２プリコーディングベクトルは、例えば、ｉ番目のユーザのＭＩＭＯチャネル行列の第２最大固有値に対応する固有ベクトルなどの行列Ｖ_ｉのＶ_ｉ２で示す第２固有ベクトルを、更新された基底

に対し直交させることにより決定される。また、

で示す第２の更新された基底は、更新された基底

を第２プリコーディングベクトル

と、例えば以下のように連結することにより決定される。

In some exemplary embodiments,

For example, the second precoding vector represented by V _i2 of the matrix V _i such as the eigen vector corresponding to the second largest eigen value of the MIMO channel matrix of the i th user is updated to the updated base.

Is determined by making them orthogonal to each other. Also,

The second updated basis indicated by is the updated basis

The second precoding vector

For example, it is determined by connecting as follows.

で示すｌ番目のプリコーディングベクトル（ｌ＝２...Ｎ_ｓｓ）は、例えば、ｉ番目のユーザのＭＩＭＯチャネル行列のｌ番目の最大固有値に対応する固有ベクトルなどの行列Ｖ_ｉのＶ_ｉｌで示されるｌ番目の固有ベクトルを、事前に更新された基底

を事前に決定された（ｌ−１）番目のプリコーディングベクトル

と連結することにより決定される更新された基底

に対し直交させることにより、例えば以下のように決定される。

In some exemplary embodiments, the operations described above are repeated, eg, to determine N _ss precoding vectors. For example,

The l-th precoding vector (l = 2... N _ss ) indicated by is represented by V _il of the matrix V _i such as the eigenvector corresponding to the l-th largest eigenvalue of the MIMO channel matrix of the i-th user, for example. The first eigenvector to be

(L-1) th precoding vector determined in advance

An updated basis determined by concatenating with

For example, it is determined as follows.

で示すビーム形成プリコーディング行列は、ｉ番目のユーザに対応するＮ_ｓｓのプリコーディングベクトルを組み合わせることにより、例えば以下のように形成される。

In some exemplary embodiments, for the i th user device

The beam forming precoding matrix indicated by is formed as follows by combining N _ss precoding vectors corresponding to the i-th user, for example.

  In some exemplary embodiments, the wireless communicator 110 may determine the K beamforming precoding matrix corresponding to each of the K user devices, for example, Equations 1, 2, 3, 4, 5, and / or Or, referring to 6, the above-described calculation is repeated.

In some exemplary embodiments, the wireless communicator 110 converts the beamforming matrix denoted B ′ used to perform the MU MIMO transmission 113 to the K user devices into the K beamforming precoding matrix. Determine based on. For example, the radio communication unit 110 determines the beam forming matrix B ′ by concatenating K beam forming precoding matrices as follows, for example.

  In some exemplary embodiments, the wireless communicator 110 transmits the multi-user MIMO transmission 113 using the beamforming matrix B ′.

  In some exemplary embodiments, the beamforming matrix determined by the operations described above with reference to Equations 1, 2, 3, 4, 5, 6, and / or 7 may be compared to, for example, receiver thermal noise. If the interference between users is dominant, for example, the signal-to-noise ratio (SNR) is relatively high, and is substantially close to the optimum state.

  FIG. 2 is a flowchart schematically illustrating a method of multi-user MIMO communication according to some exemplary embodiments. In some exemplary embodiments, one or more operations of the method illustrated in FIG. 2 may include one or more elements of a system, such as system 100 (100), for example, wireless communication devices 102, 104, 106 and / or 108. Performed by one or more wireless communication devices such as (FIG. 1), for example, one or more wireless communication units such as wireless communication units 110 and / or 124 (FIG. 1), and / or any other element. In some embodiments, one or more operations of the method shown in FIG. 2 include an MBD algorithm that includes one or more of the operations described above with reference to, for example, Equations 1, 2, 3, 4, 5, 6, and / or 7. As part of the run.

  As indicated at block 202, the method includes receiving at the wireless communication device a plurality of channel feedback transmissions from each of the plurality of user devices. The channel feedback transmission from one user device of the plurality of user devices may include partial information regarding a multi-user MIMO channel matrix between the wireless communication unit and the user device. For example, the wireless communication unit 110 (FIG. 1) of the wireless communication device 102 (FIG. 1) receives multiple channel feedback transmissions from the wireless communication devices 104, 106 and / or 108 (FIG. 1), for example, as described above. .

  As shown in block 201, the method includes performing channel feedback transmission from at least one user device, eg, from each of the user devices, to the wireless communication device.

In some exemplary embodiments, the channel feedback transmission represents a plurality of eigenvectors corresponding to, for example, a MIMO channel matrix between the user and the wireless communication device. For example, the wireless communication unit 124 (FIG. 1) of the i-th user transmits the channel feedback transmission representing the matrix V _i to the wireless communication unit 110 (FIG. 1), for example, as described above with reference to FIG.

  As shown in block 204, the method includes determining a MIMO beamforming scheme based on a plurality of channel feedback transmissions. In some exemplary embodiments, determining the MIMO beamforming scheme includes determining the MIMO beamforming scheme according to the MBD algorithm. For example, the wireless communication unit 110 (FIG. 1) determines a MIMO beamforming scheme based on channel feedback transmissions received from the wireless communication devices 104, 106 and / or 108 (FIG. 1).

  As indicated at block 208, determining the MIMO beamforming scheme may include selecting the i th user. For example, one or more operations described below with reference to blocks 210, 212, 214, 216, 218, 220 and / or 224 are repeated for one or more users, eg, all users. Thus, in the first of the repeated operations, the method may include selecting the first user.

を決定することを含んでよい。 As shown in block 210, the MIMO beamforming scheme is determined, for example, as described above with reference to Equation 1 as an interference matrix.

May be included.

のＳＶＤを決定することを含んでよい。 As shown in block 212, the MIMO beamforming scheme is determined, for example, as described above with reference to Equation 2 as an interference matrix.

Determining an SVD of the

の固有ベクトルの組を含む、基底

を決定することを含んでよい。 As shown at block 214, the method may include determining a basis of a space that is generated by all dominant eigenvectors of users other than the i th user. For example, the determination of the basis can be done by, for example, a matrix corresponding to a non-zero singular value as described above.

A basis containing a set of eigenvectors of

May be included.

を決定することを含んでよい。例えば、プリコーディングベクトル

の決定は、例えば図１を参照して上述したように、行列Ｖ_ｉの第１固有ベクトル

を、基底

に対し直交させることを含んでよい。 As shown in block 216, the MIMO beamforming scheme is determined by the precoding vector.

May be included. For example, precoding vector

Is determined by, for example, the first eigenvector of the matrix V _i , as described above with reference to FIG.

The base

May be orthogonal.

に基づいて更新された基底を決定することを含んでよい。例えば、更新された基底の決定は、例えば数式３を参照して上述したように、基底

およびプリコーディングベクトル

に基づいて基底

を決定することを含んでよい。 As shown in block 218, the determination of the MIMO beamforming scheme is based on a basis.

Determining an updated basis based on. For example, the updated basis determination may be performed as described above with reference to Equation 3, for example.

And precoding vector

Based on

May be included.

を決定することを含んでよい。例えば、プリコーディングベクトル

の決定は、例えば図１を参照し上述したように、行列Ｖ_ｉの第２固有ベクトルＶ_ｉ２を、更新された基底

に対し直交させることを含んでよい。 As shown in block 220, the MIMO beamforming scheme is determined by the following precoding vector:

May be included. For example, precoding vector

For example, as described above with reference to FIG. 1, the second eigenvector V _i2 of the matrix V _i is updated to the updated basis.

May be orthogonal.

As shown at block 222, determining the MIMO beamforming scheme may include repeating the operations of blocks 218 and 220 until, for example, determining N _ss precoding vectors, eg, as described above.

  As shown in blocks 224, 225, the determination of the MIMO beamforming scheme increases the value of i and the operation of blocks 208, 210, 212, 214, 216, 218, 220 and / or 222 for the next user. May include determining, for example, as described above, K beamforming precoding matrices corresponding to each of the K user devices.

  As shown in block 226, determining the MIMO beamforming scheme may include determining a beamforming matrix based on the K beamforming precoding matrices. For example, determining the beamforming matrix may include determining the matrix B ′ as described above with reference to Equation 7, for example.

  As shown at block 206, the method may include performing multi-user MIMO transmission from the wireless communication device to multiple users in accordance with a MIMO beamforming scheme based on multiple channel feedback transmissions. For example, the radio communication unit 110 (FIG. 1) transmits the multi-user MIMO transmission 113 (FIG. 1) using the beam forming matrix B ′ as described above, for example.

  FIG. 3 is a graph 302 that schematically represents ergodic capacity as a function of SNR for multi-user MIMO transmission with channel feedback including partial MIMO channel information, in accordance with some exemplary embodiments.

Graph 302 shows in units of bits per second per Hertz (Hz) for an 8x2 antenna configuration with three user devices, a stream of N _ss = 2 and a channel compliant with IEEE 802.11 TGac Model D. Represents ergodic capacity results.

  Graph 302 represents the ergodic capacity obtained by the MBD algorithm, for example as described above with reference to FIG. As shown in FIG. 3, the result obtained according to the MBD algorithm is similar to the result obtained using the conventional BD algorithm. However, in contrast to the conventional BD scheme, the MBD algorithm requires partial MIMO channel matrix feedback information.

  Referring again to FIG. 1, in some exemplary embodiments, channel feedback transmission from one or more user devices corresponds to the quality of the channel between the wireless communicator and each of the one or more user devices. May represent a channel quality indicator. For example, the first channel feedback transmission represents a channel quality indicator corresponding to the quality of the channel between the wireless communication unit 110 and the user device 104, and the second channel feedback transmission is between the wireless communication unit 110 and the user device 106. The channel quality indicator corresponding to the quality of the channel between and / or the third channel feedback transmission represents the channel quality indicator corresponding to the quality of the channel between the wireless communicator 110 and the user device 108.

  In some exemplary embodiments, the channel quality indicator from the user device may include SNR, signal-to-noise interference ratio (SINR), modulation coding corresponding to a channel between the wireless communication unit 110 and the user device. It represents at least one of the schemes (MCS). In other embodiments, the channel feedback transmission includes other suitable information regarding and / or representing the channel between the wireless communicator 110 and the user device. While some exemplary embodiments are described below taking SNR, other embodiments may be implemented with other suitable channel quality indicators or parameters.

  In some exemplary embodiments, the wireless communicator 110 determines a beamforming scheme for the MU MIMO transmission 113 based on the received channel quality indicator, eg, as described below.

の固有値分解を行うことにより決定される。ここで

は、例えば

などの対角行列を指し、ここでρ_ｉｊは、ｉ番目のユーザのｊ番目のＳＮＲを指し、ここでｊ＝ｌ...Ｎ_ｓｓであり、ここで

は次元Ｍ_Ｔの恒等行列を指し、ここで

は、スケーリングされていない基底行列を指し、ここで、

は、スケーリング行列を指す。 In some exemplary embodiments, the vector basis is related to the i th user, for the space generated by the scaled eigenvectors of all users other than the i th user, eg, a matrix

Is determined by performing eigenvalue decomposition of. here

For example

Where ρ _ij refers to the j th SNR of the ith user, where j = 1 ... N _ss , where

Refers to identity matrix of dimension M _T is here

Refers to an unscaled basis matrix, where

Refers to the scaling matrix.

で示すスケーリングされていない基底行列は、以下のように定義することが出来る。

In some exemplary embodiments,

The unscaled basis matrix can be defined as follows:

のカラムが生成する空間へ投影される。行列Ｖ_ｉに、例えばＮ_ｓｓのストリームのＳＮＲの影響を反映させるべく、例えば、行列Ｖ_ｉを投影する前に、対角行列Ｄ_ｉ＝ｄｉａｇ（ρ_１...ρ_ｉＮｓｓ）の平方根を事前に乗算する。例えば、事前に乗算されたマトリクスＶ_ｉの投影により、例えば

で表される、投影された行列

が得られる。 In some exemplary embodiments, the matrix V _i is a matrix

Are projected onto the generated space. Pre matrix _{V i,} for example, to reflect the impact of SNR of _{N ss} streams, for example, before projecting the matrix _{V i,} the diagonal matrix _D i = diag the square root of _{(ρ 1} ... ρ iNss) Multiply by. For example, by projection of a pre-multiplied matrix V _i , for example

Projected matrix represented by

Is obtained.

のＳＶＤを実行し、

を得る。ここで、Ｙ_ｉは行列

を含むＭ'で示すフィールドの（Ｍ_Ｔ−ｂｙ−Ｍ_Ｔ）のユニタリ行列を指し、ここでΣ_ｉは、対角線に非負実数を有する（Ｍ_Ｔ−ｂｙ−Ｎ_ｓｓ）対角行列を指し、ここでＷ_ｉは、Ｍ'の（Ｎ_ｓｓ−ｂｙ−Ｎ_ｓｓ）のユニタリ行列を指し、ここで

は、Ｗ_ｉの共役転置を指す。 In some exemplary embodiments, the wireless communicator 110 may use the projected interference matrix of Equation 11

Run SVD,

Get. Where Y _i is a matrix

(M _T -by-M _T ) unitary matrix of the field denoted by M ′, where Σ _i refers to a diagonal matrix having a non-negative real number on the diagonal (M _T -by-N _ss ), Here, W _i refers to the unitary matrix of (N _ss -by-N _ss ) of M ′, where

Refers to the conjugate transpose of _{W i.}

で示されるｉ番目のユーザのビーム形成行列は、行列

の残された支配的な固有ベクトルのうち最初のＮ_ｓｓの固有ベクトルを含む。 In some exemplary embodiments, the wireless communicator 110 determines K beamforming matrices corresponding to the K user devices. here,

The beam forming matrix of the i-th user denoted by

Of the remaining dominant eigenvectors of the first N _ss .

のように連結することにより、ビーム形成行列Ｂ"を決定する。 In some exemplary embodiments, the wireless communicator 110 determines a beamforming matrix denoted B ″ used to perform MU MIMO transmission 113 to K user devices based on the K beamforming matrix. For example, the wireless communication unit 110 uses a beam forming matrix of K, for example,

The beam forming matrix B ″ is determined by connecting as follows.

  FIG. 4 is a flowchart schematically illustrating a method of multi-user MIMO communication, according to some exemplary embodiments. In some exemplary embodiments, one or more operations of the method illustrated in FIG. 4 may include one or more elements of a system, such as system 100 (100), for example, wireless communication devices 102, 104, 106 and / or 108. Performed by one or more wireless communication devices such as (FIG. 1), for example, one or more wireless communication units such as wireless communication units 110 and / or 124 (FIG. 1), and / or any other element. In some embodiments, one or more operations of the method shown in FIG. 4 are one of the MRBD algorithms that include one or more of the operations described above with reference to, for example, Equations 8, 9, 10, 11, 12, and / or 13. It is executed as a part.

  As shown in block 402, the method includes receiving at the wireless communication device a plurality of channel feedback transmissions from each of the plurality of user devices. The channel feedback transmission from one user device of the plurality of user devices may include partial information regarding a multi-user MIMO channel matrix between the wireless communication unit and the user device. The channel feedback transmission from the user may also represent a channel quality indicator corresponding to the quality of the channel between the wireless communication device and the user. For example, the wireless communication unit 110 (FIG. 1) of the wireless communication device 102 (FIG. 1) receives multiple channel feedback transmissions from the wireless communication devices 104, 106 and / or 108 (FIG. 1), for example, as described above. .

  As shown in block 401, the method includes performing a channel feedback transmission from at least one user device, such as from each of the user devices, to the wireless communication device.

In some exemplary embodiments, the channel feedback transmission represents a plurality of eigenvectors corresponding to, for example, a MIMO channel matrix between the user and the wireless communication device. For example, the wireless communication unit 124 (FIG. 1) of the i-th user sends the channel feedback transmission representing the matrix V _i and the channel quality indicator to the wireless communication unit 110 (FIG. 1), for example, as described above with reference to FIG. Send.

  As shown in block 404, the method includes determining a MIMO beamforming scheme based on a plurality of channel feedback transmissions. In some exemplary embodiments, determining the MIMO beamforming scheme includes determining the MIMO beamforming scheme according to the MRBD algorithm. For example, the wireless communication unit 110 (FIG. 1) determines a MIMO beamforming scheme based on channel feedback transmission received from the wireless communication devices 104, 106 and / or 108 (FIG. 1), for example, as described above.

  As indicated at block 408, determining the MIMO beamforming scheme may include selecting the i th user. For example, one or more operations described below with reference to blocks 410, 412, 414, 416, 418 and / or 420 are repeated for one or more users, eg, all users. Thus, in the first of the repeated operations, the method may include selecting the first user.

を決定することを含んでよい。 As shown in block 410, the MIMO beamforming scheme is determined as described above with reference to Equation 1 as an interference matrix.

May be included.

および、例えば行列

などのチャネル品質情報に基づく行列

などの行列のＳＶＤを決定することを含んでよい。 As shown in block 412, the MIMO beamforming scheme is determined by, for example, the interference matrix as described above.

And, for example, a matrix

Matrix based on channel quality information such as

Determining the SVD of the matrix.

を決定することを含んでよい。 As shown in block 414, the method may include an unscaled basis matrix based on SVD, eg, as described above with reference to Equation 10.

May be included.

As shown in block 416, the method may _{divide the} channel quality information by pre-multiplying the matrix V _i by, for example, the square root of the diagonal matrix D _i = diag (ρ _i1 . it may include applying to the eigenvector matrix V _i.

のカラムが生成する空間へ投影することを含んでよい。 As shown in block 418, the method may use a pre-multiplied matrix V _i as described above with reference to Equation 11, for example.

Projecting into the generated space.

の残された支配的な固有ベクトルのうち最初のＮ_ｓｓの固有ベクトルを選択することを含んでよい。 As shown at block 420, the method may include determining a beamforming matrix corresponding to the i th user based on the projected interference matrix. For example, the determination of the beamforming matrix corresponding to the i th user can be accomplished by performing SVD of the projected interference matrix, eg, as described above,

Selecting the first N _ss eigenvectors of the remaining dominant eigenvectors.

  As shown in blocks 422 and 423, the determination of the MIMO beamforming scheme increases the value of i and repeats the operations of blocks 408, 410, 412, 414, 416, 418 and / or 420 for the next user. Thus, for example, as described above, for example, may include determining K beamforming precoding matrices corresponding to each of the K user devices.

  As shown in block 424, determining the MIMO beamforming scheme may include determining a beamforming matrix based on the K beamforming precoding matrices. For example, determining the beamforming matrix may include determining the matrix B ″ as described above with reference to Equation 13.

  As shown in block 406, the method may include performing multi-user MIMO transmission from the wireless communication device to multiple users in accordance with a MIMO beamforming scheme based on multiple channel feedback transmissions. For example, the radio communication unit 110 (FIG. 1) transmits the multiuser MIMO transmission 113 (FIG. 1) using the beam forming matrix B ″ as described above, for example.

  FIG. 5 schematically represents ergodic capacity as a function of SNR for multi-user MIMO transmission utilizing channel feedback including channel quality indication and partial MIMO channel information, in accordance with some exemplary embodiments. It is a graph 502.

Graph 502 shows in units of bits per second per Hertz (Hz) for an 8x2 antenna configuration with three user devices, a stream of N _ss = 2 and a channel compliant with IEEE 802.11 TGac Model D. Represents ergodic capacity results. Graph 502 represents the ergodic capacity obtained by the MRBD algorithm, for example, as described above with reference to FIG. As shown in FIG. 5, the results obtained according to the MRBD algorithm are similar to the results obtained using the conventional RBD algorithm. However, in contrast to the conventional RBD scheme, the MRBD algorithm requires partial MIMO channel matrix feedback information.

  FIG. 6 is a schematic diagram of an article 600 according to some exemplary embodiments. Article 600 performs, for example, at least some of the functions of wireless communication unit 110 (FIG. 1) and / or wireless communication unit 124 (FIG. 1), and / or one or more of the methods of FIGS. 2 and / or 4 A machine-readable storage medium 602 that stores logic 604 used to perform the operations may be included.

  In some embodiments, the article 600 and / or machine-readable storage medium 602 may be volatile memory, non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writable or rewritable. It may include one or more types of computer readable storage media capable of storing data, including memory and the like. For example, the machine-readable storage medium 602 includes a random access memory (RAM), a dynamic RAM (DRAM), a double data rate DRAM (DDR-DRAM), a synchronous DRAM (SDRAM), a static RAM (SRAM), and a read only memory (ROM). ), Programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), compact disc ROM (CD-ROM), recordable compact disc (CD-R), rewritable Compact disk (CD-RW), flash memory (eg, NOR or NAND flash memory), content addressable memory (CAM), polymer memory, phase change memory, ferroelectric memory, silicon-oxide-nitride Oxide - containing silicon (SONOS) memory, disk, floppy disk, hard drive, Opti Cal disks, magnetic disks, cards, magnetic cards, Opti Cal card, tape, cassette, or the like. A computer readable storage medium is a download of a computer program carried from a remote computer to a requesting computer by means of a data signal in the form of a carrier wave or other propagation medium, for example via a communication link such as a modem, wireless or network connection Includes any suitable medium associated with the transfer.

  In some embodiments, the logic 604 includes instructions, data, and / or code that, when executed on a machine, causes the machine to perform the methods, processes, and / or operations described herein. The machine includes, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, etc., and any suitable hardware, software, firmware, etc. You may implement using various combinations.

  In some embodiments, the logic 604 may include or be implemented as software, software modules, applications, programs, subroutines, instructions, instruction sets, computing code, words, values, signs, etc. The instructions include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. The instructions may be implemented according to a predefined computer language, manner or syntax that instructs the processor to perform a predetermined function. The instructions are C, C ++, Java, BASIC, Matlab, Pascal, Visual BASIC, assembly language, machine code, etc. Any suitable high-level, low-level, object-oriented, compiled, and It may be implemented using an interpreted programming language.

  A function, operation, component and / or feature described herein with reference to one or more embodiments is equivalent to another function, operation, component described with reference to one or more other embodiments herein. And / or can be used in combination with one or more of the features, or in combination, and vice versa.

  While several features of the present invention have been shown and described herein, many modifications, alternatives, changes and equivalents will occur to those skilled in the art. Accordingly, the following claims are intended to cover all such modifications and changes as falling within the spirit of the invention.

Claims (28)

A wireless communication unit for transmitting multi-user MIMO transmission to a plurality of user devices according to a multiple-input multiple-output (MIMO) beamforming scheme;
The wireless communication unit receives a plurality of channel feedback transmissions from each of the plurality of user devices;
One channel feedback transmission from one user device of the plurality of user devices represents a plurality of eigenvectors corresponding to a MIMO channel matrix between the wireless communication unit and the one user device,
The wireless communication unit is a wireless communication device that determines the MIMO beamforming method based on the plurality of channel feedback transmissions. The multi-user MIMO transmission includes two or more transmission streams directed to the one user device;
The wireless communication device according to claim 1, wherein the number of the plurality of eigenvectors represented by the one channel feedback transmission is equal to the number of the two or more transmission streams.   The wireless communication device according to claim 1 or 2, wherein the one channel feedback transmission represents a plurality of dominant eigenvectors respectively corresponding to a plurality of dominant eigenvalues of the MIMO channel matrix. The wireless communication unit determines the MIMO beamforming method based on the plurality of eigenvectors corresponding to the one user device and based on a plurality of interference matrices corresponding to each of the plurality of user devices,
4. The wireless communication according to claim 1, wherein one interference matrix corresponding to the one user device includes a plurality of eigenvectors corresponding to other user devices among the plurality of user devices. 5. device. The one channel feedback transmission represents a channel quality indicator corresponding to the quality of the channel between the wireless communicator and the one user device;
The wireless communication device according to claim 1, wherein the wireless communication unit determines the beamforming method based on the channel quality indicator.   The wireless communication device of claim 5, wherein the channel quality indicator represents at least one of a signal to noise ratio, a signal to noise interference ratio, and a modulation and coding scheme.   6. The wireless communication device of claim 1, wherein the one feedback transmission includes a codebook index representing a plurality of predefined vectors approximating the plurality of eigenvectors of the MIMO channel matrix. .   The wireless communication device according to claim 1, wherein the multi-user MIMO transmission includes two or more transmission streams directed to each of the plurality of user devices. A wireless communication device comprising: a plurality of antennas; and a wireless communication unit that transmits multi-user MIMO transmission to a plurality of user devices according to a multiple-input multiple-output (MIMO) beamforming scheme. Receive multiple channel feedback transmissions from each,
One channel feedback transmission from one user device of the plurality of user devices includes partial information regarding a MIMO channel matrix between the wireless communication unit and the one user device;
The wireless communication system, wherein the wireless communication unit determines the MIMO beamforming method based on the plurality of channel feedback transmissions.   The wireless communication system according to claim 9, wherein the one channel feedback transmission represents a plurality of eigenvectors corresponding to the MIMO channel matrix. The multi-user MIMO transmission includes two or more transmission streams directed to the one user device;
The wireless communication system according to claim 10, wherein the number of the plurality of eigenvectors represented by the one channel feedback transmission is equal to the number of the two or more transmission streams.   The wireless communication system according to claim 10 or 11, wherein the one channel feedback transmission represents a plurality of dominant eigenvectors respectively corresponding to a plurality of dominant eigenvalues of the MIMO channel matrix. The wireless communication unit determines the MIMO beamforming method based on the plurality of eigenvectors corresponding to the one user device and based on a plurality of interference matrices corresponding to each of the plurality of user devices,
The wireless communication according to any one of claims 10 to 12, wherein one interference matrix corresponding to the one user device includes a plurality of eigenvectors corresponding to other user devices among the plurality of user devices. system.   The wireless communication system according to any one of claims 10 to 13, wherein the one feedback transmission includes a codebook index representing a plurality of predefined vectors corresponding to the plurality of eigenvectors of the MIMO channel matrix. . The one channel feedback transmission represents a channel quality indicator corresponding to the quality of the channel between the wireless communicator and the one user device;
The wireless communication system according to claim 9, wherein the wireless communication unit determines the beamforming method based on the channel quality indicator.   The wireless communication system according to any one of claims 9 to 15, wherein the multi-user MIMO transmission includes two or more transmission streams directed to each of the plurality of user devices.   The wireless communication system according to claim 9, comprising the one user device. In the wireless communication department,
Receiving a plurality of channel feedback transmissions from each of a plurality of user devices, and transmitting a multi-user MIMO transmission to the plurality of user devices according to a multiple-input multiple-output (MIMO) beamforming scheme,
One channel feedback transmission from one user device of the plurality of user devices includes partial information regarding a MIMO channel matrix between the wireless communication unit and the one user device;
The MIMO beamforming scheme is based on the plurality of channel feedback transmissions.   The method of claim 18, wherein the one channel feedback transmission represents a plurality of eigenvectors corresponding to the MIMO channel matrix. The multi-user MIMO transmission includes two or more transmission streams directed to the one user device;
The method of claim 19, wherein the number of the plurality of eigenvectors represented by the one channel feedback transmission is equal to the number of the two or more transmission streams.   21. A method according to claim 19 or 20, wherein the one channel feedback transmission represents a plurality of dominant eigenvectors respectively corresponding to a plurality of dominant eigenvalues of the MIMO channel matrix. Determining the MIMO beamforming scheme based on the plurality of eigenvectors corresponding to the one user device and based on a plurality of interference matrices corresponding to each of the plurality of user devices;
The method according to any one of claims 19 to 21, wherein one interference matrix corresponding to the one user device includes a plurality of eigenvectors corresponding to other user devices of the plurality of user devices.   23. A method according to any one of claims 18 to 22, wherein the one channel feedback transmission represents a channel quality indicator corresponding to the quality of the channel between the wireless communicator and the one user device.   24. A method according to any one of claims 18 to 23, wherein the multi-user MIMO transmission comprises two or more transmission streams directed to each of the plurality of user devices. A wireless communication unit for transmitting channel feedback transmission to a wireless communication station;
The channel feedback transmission represents a plurality of eigenvectors corresponding to a multiple-input multiple-output (MIMO) channel matrix between the wireless communication unit and the wireless communication station,
The wireless communication unit receives a plurality of transmission streams of multi-user transmission from the wireless communication station according to a MIMO beamforming method,
The MIMO beamforming scheme is a wireless communication device based on the channel feedback transmission.   26. The wireless communication device of claim 25, wherein the channel feedback transmission represents a plurality of dominant eigenvectors that respectively correspond to a plurality of dominant eigenvalues of the MIMO channel matrix.   27. The wireless communication device according to claim 25 or 26, wherein a number of the plurality of eigenvectors is equal to a number of the plurality of transmission streams.   The wireless communication device according to any one of claims 25 to 27, wherein the channel feedback transmission represents a channel quality indicator corresponding to a quality of a channel between the wireless communication unit and the wireless communication station.

Images